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Natural hazard risk in St. Thomas Island, Virgin Islands

Updated October 30, 2026. Based on FEMA, NOAA and OpenFEMA data. Published by Humblebee.

FEMA overall risk rating
Insufficient Data[1]
Expected annual loss (FEMA)
$73.0 million[2]
Federal disaster declarations since 1970
26[3]
NFIP flood claims paid, 1978 to 2026
$37.3 million[4]

FEMA's National Risk Index (version 1.20, December 2025) has no overall Risk Index rating for the county and lists it as Insufficient Data[1]. FEMA does publish Expected Annual Loss, and the largest hazard-type values are hurricane, tsunami and earthquake[5].

FEMA risk ratings for each hazard

Ratings and expected losses from the FEMA National Risk Index. Each rating compares this county with all US counties for that hazard, from Very Low to Very High. They are planning estimates, not predictions, and they do not describe any single property.

FEMA estimates Expected Annual Loss from all 18 natural hazards at $73.0 million a year, with an Expected Annual Loss rating of Relatively Moderate[2]. Of this, FEMA attributes $50.6 million to buildings and $22.3 million to injuries and deaths, which it converts to dollars[2]. By hazard type, the largest values are hurricane at $40.3 million a year, tsunami at $16.8 million a year and earthquake at $13.3 million a year[5]. FEMA rates hurricane Expected Annual Loss Relatively High compared with other US counties[6]. FEMA says Expected Annual Loss is an estimate of average yearly loss and does not predict next year's damage[7]. The facts for this county do not include social vulnerability or community resilience ratings.

Hazards sorted by FEMA hazard-type Risk Index score, highest first
HazardFEMA risk ratingExpected annual loss
Coastal FloodingInsufficient Data$79,000[8]
EarthquakeInsufficient Data$13.3 million[9]
HailInsufficient Data$335[10]
HurricaneInsufficient Data$40.3 million[6]
Inland FloodingInsufficient Data$2.5 million[11]
Strong WindInsufficient Data$333[12]
TornadoInsufficient Data$4,478[13]
TsunamiInsufficient Data$16.8 million[14]
Volcanic ActivityInsufficient Data$995[15]

Rated Not Applicable by FEMA for this county: avalanche, ice storm[16].

Flooding and flood insurance

FEMA rates inland flooding Expected Annual Loss Very Low and coastal flooding Relatively Low compared with other US counties[11][8]. HazardFacts tallied OpenFEMA NFIP claims for losses from 1978 to 2026 and found 1,386 claims in the county, 821 of them with a payment[4]. NFIP paid $37.3 million in total[4]. The years with the most paid claims were 1995, 1989 and 2017[4]. County ratings do not tell you the flood zone of an address, so use FEMA's Flood Map Service Center[17].

Measure Value
Coastal Flooding, FEMA risk rating[8] Insufficient Data, $79,000 expected loss a year
Inland Flooding, FEMA risk rating[11] Insufficient Data, $2.5 million expected loss a year
NFIP flood claims, 1978 to 2026[4] 1,386 filed, $37.3 million paid

Is a specific address in a flood zone? Only FEMA's flood maps answer that, property by property[17]. This page describes the whole county.

Search an address on the FEMA Flood Map Service Center

Disaster declarations and tornado records

OpenFEMA lists 26 federal disaster declarations for natural hazards that include the county since 1970[3]. Of these, 18 were major disaster declarations and 8 were emergency or fire management declarations[3]. By incident type, OpenFEMA lists hurricane 17, flood 3, drought 2, severe storm 2 and tropical storm 2[3]. The most recent listed is DR-4841-VI for Tropical Storm Ernesto, declared 2024-10-25[18].

Federal disaster declarations for natural hazards that include St. Thomas Island, since 1970
Incident type Declarations
Hurricane[3] 17
Flood[3] 3
Drought[3] 2
Severe Storm[3] 2
Tropical Storm[3] 2
Most recent declarations
Declaration Incident Declared
DR-4841-VI[18] Tropical Storm Ernesto 2024-10-25
EM-3611-VI[18] Tropical Storm Ernesto 2024-08-18
EM-3531-VI[18] Potential Tropical Cyclone Nine 2020-07-29
EM-3418-VI[18] Hurricane Dorian 2019-08-28
DR-4340-VI[18] Hurricane Maria 2017-09-20

How to prepare

Steps from Ready.gov, FEMA's preparedness site, for the hazards with the highest FEMA ratings here. Follow instructions from local officials and the National Weather Service when a warning is issued.

Earthquakes

Before

  • Practice Drop, Cover, and Hold On with your family and coworkers.
  • Sign up for earthquake alerts that can warn you before shaking starts.
  • Make a plan with an out-of-state contact and a place to meet if you get separated.
  • Anchor heavy items such as bookcases, refrigerators and water heaters, and keep heavy things on low shelves.
  • Consider earthquake insurance. Standard homeowners policies do not cover earthquake damage.

During

  • Drop to your hands and knees, cover your head and neck, and hold on until the shaking stops.
  • Indoors, stay where you are and avoid doorways. Outdoors, move to an open area away from buildings and power lines.
  • If you are driving, pull over, stop and set the parking brake.

Source: Ready.gov, earthquakes

Hurricanes

Before

  • Know your hurricane risk, including rain, wind and tornadoes far inland from landfall.
  • Learn your evacuation zone and routes, and practice them with your household and pets.
  • Keep insurance policies and ID current, with password-protected digital copies.
  • Clear drains and gutters, bring in outdoor furniture and consider hurricane shutters.
  • Keep your phone charged, buy backup chargers and gather supplies, including medication and pet supplies.

During

  • If you are in a mandatory evacuation zone and officials order an evacuation, leave right away.
  • For high winds, take shelter in a designated storm shelter or an interior room.
  • If you are trapped by flooding, go to the highest level, but do not climb into a closed attic.

Source: Ready.gov, hurricanes

Questions people ask

Is the county at risk of hurricanes?
FEMA rates hurricane Expected Annual Loss Relatively High compared with other US counties, at $40.3 million a year[6]. OpenFEMA lists 17 hurricane declarations that include the island since 1970[3].
Is the county at risk of earthquakes?
FEMA rates earthquake Expected Annual Loss Relatively Moderate at $13.3 million a year[9]. Earthquake is the third largest hazard-type value in the county[5].
Is the county at risk of tornadoes?
FEMA rates tornado Expected Annual Loss Very Low at $4,478 a year[13]. FEMA says a hazard can still cause damage where a rating is low[7].
How many disasters were declared for the county?
OpenFEMA lists 26 federal disaster declarations for natural hazards that include the county since 1970[3].
How do I check a flood zone for an address?
FEMA's Flood Map Service Center is the official public source for flood maps, and you can look up an address there[17]. County-level ratings do not give the flood zone of one address[17].

Facts and sources

  1. FEMA National Risk Index (version 1.20, December 2025): St. Thomas Island has no overall Risk Index rating; FEMA lists it as Insufficient Data. For US territories FEMA publishes Expected Annual Loss but not the full Risk Index. FEMA National Risk Index
  2. FEMA National Risk Index (version 1.20, December 2025): Expected Annual Loss from all 18 natural hazards in St. Thomas Island is $73.0 million a year (Expected Annual Loss rating Relatively Moderate, score 88.1). Of this, buildings account for $50.6 million, injuries and deaths (converted to dollars by FEMA) for... FEMA National Risk Index
  3. OpenFEMA Disaster Declarations Summaries list 26 federal disaster declarations for natural hazards that include St. Thomas Island since 1970 (18 major disaster, 8 emergency or fire management). By incident type: hurricane 17, flood 3, drought 2, severe storm 2, tropical storm 2. Biological (such as COVID-19) and... OpenFEMA Disaster Declarations
  4. HazardFacts tally of OpenFEMA NFIP Redacted Claims (losses from 1978 to 2026): 1,386 National Flood Insurance Program claims were filed for losses in St. Thomas Island, 821 of them with a payment, and NFIP paid $37.3 million in total (building, contents and increased cost of compliance, in dollars of the year... OpenFEMA NFIP claims
  5. HazardFacts sorted FEMA's hazard-type Expected Annual Loss values for St. Thomas Island (National Risk Index v1.20): the largest are hurricane ($40.3 million a year), tsunami ($16.8 million a year), earthquake ($13.3 million a year), out of $73.0 million a year from all 18 hazards. FEMA National Risk Index
  6. FEMA National Risk Index (version 1.20, December 2025), hurricane in St. Thomas Island: Risk Index rating listed as Insufficient Data. Expected Annual Loss $40.3 million a year (rating Relatively High). Annualized frequency 0.26 events per year, from recorded occurrences over a period of record of 172 years for the... FEMA National Risk Index
  7. FEMA's National Risk Index FAQ (December 2025): Expected Annual Loss is FEMA's estimate of the average economic loss in dollars from natural hazards each year. The index is not meant to predict how much damage a community will have in the next year, and a hazard can still cause damage where a rating is low. Scores... FEMA National Risk Index documentation
  8. FEMA National Risk Index (version 1.20, December 2025), coastal flooding in St. Thomas Island: Risk Index rating listed as Insufficient Data. Expected Annual Loss $79,000 a year (rating Relatively Low). FEMA's modeled annual frequency is 0.21 events per year. FEMA National Risk Index
  9. FEMA National Risk Index (version 1.20, December 2025), earthquake in St. Thomas Island: Risk Index rating listed as Insufficient Data. Expected Annual Loss $13.3 million a year (rating Relatively Moderate). FEMA's modeled annual frequency is 0.0693 events per year. FEMA National Risk Index
  10. FEMA National Risk Index (version 1.20, December 2025), hail in St. Thomas Island: Risk Index rating listed as Insufficient Data. Expected Annual Loss $335 a year (rating Very Low). Annualized frequency 0 events per year, from recorded occurrences over a period of record of 37 years. FEMA National Risk Index
  11. FEMA National Risk Index (version 1.20, December 2025), inland flooding in St. Thomas Island: Risk Index rating listed as Insufficient Data. Expected Annual Loss $2.5 million a year (rating Very Low). Annualized frequency 0.79 event-days per year, from recorded occurrences over a period of record of 26 years. FEMA National Risk Index
  12. FEMA National Risk Index (version 1.20, December 2025), strong wind in St. Thomas Island: Risk Index rating listed as Insufficient Data. Expected Annual Loss $333 a year (rating Very Low). Annualized frequency 0 events per year, from recorded occurrences over a period of record of 38 years. FEMA National Risk Index
  13. FEMA National Risk Index (version 1.20, December 2025), tornado in St. Thomas Island: Risk Index rating listed as Insufficient Data. Expected Annual Loss $4,478 a year (rating Very Low). Annualized frequency 0 events per year, from recorded occurrences over a period of record of 38 years. FEMA National Risk Index
  14. FEMA National Risk Index (version 1.20, December 2025), tsunami in St. Thomas Island: Risk Index rating listed as Insufficient Data. Expected Annual Loss $16.8 million a year (rating Relatively Moderate). FEMA National Risk Index
  15. FEMA National Risk Index (version 1.20, December 2025), volcanic activity in St. Thomas Island: Risk Index rating listed as Insufficient Data. Expected Annual Loss $995 a year (rating Very Low). FEMA National Risk Index
  16. FEMA National Risk Index (version 1.20, December 2025) rates these hazards Not Applicable for St. Thomas Island: avalanche, ice storm. FEMA uses Not Applicable when its source data has no historical record of the hazard in the community and the hazard is not considered geographically possible there. FEMA National Risk Index documentation
  17. FEMA's Flood Map Service Center is the official public source for flood maps (Flood Insurance Rate Maps) produced under the National Flood Insurance Program. Flood zones apply to specific properties: look up an address there or ask the local floodplain manager. County-level ratings do not tell you the flood zone of... FEMA Flood Map Service Center
  18. Most recent federal disaster declarations for natural hazards (table on this page). OpenFEMA Disaster Declarations

FEMA's National Risk Index compares each county with all other US counties. Ratings are relative (Very Low to Very High), not a measure of safety. Never call a place safe, unsafe, good or bad to live in. Risk Index and Expected Annual Loss values are FEMA estimates for planning. They do not predict next year's losses and do not apply to a single property. Flood zones are set by FEMA flood maps for specific properties. County ratings and flood insurance counts do not tell anyone whether an address is in a flood zone. Disaster declaration, NFIP and tornado counts are records of the past for this county only. Do not compare with other counties unless a fact does.

Federal Emergency Management Agency (FEMA), National Risk Index Dataset: National Risk Index Counties, v1.20 (December 2025). Retrieved from fema.maps.arcgis.com on October 30, 2026. This product uses the Federal Emergency Management Agency's National Risk Index dataset API or downloadable datasets but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s). This product uses the FEMA OpenFEMA API, but is not endorsed by FEMA.